   //替换URL参数
        function changeURLArg(url, arg, arg_val){
            var pattern = arg + '=([^&]*)';
            var replaceText = arg + '=' + arg_val;
            if (url.match(pattern)){
                var tmp = '/(' + arg + '=)([^&]*)/gi';
                tmp = url.replace(eval(tmp), replaceText);
                return tmp;
            } else{
                if (url.match('[\?]')){
                    return url + '&' + replaceText;
                } else{
                    return url + '?' + replaceText;
                }
            }
            return url + '\n' + arg + '\n' + arg_val;
        }